You shouldnt be worrying too much providing you are taking the pill properly and regulary. But there are a few factors maybe you should be aware of. For one, the pill is never 100% protection (I know!!!) If you are ill, physically sick, have diarrhoea, or taking anti biotics, this is very likely to stop the pill from working properly. I fell pregnant on the pill with my daughter simply from having a bad cold!
You might think about using condoms too? The pill, Im assuming this is the birth control you are referring to, wont protect against STD's.